With some changes I was able to run the DRLVM with classlib's launcher. Here is what I did (you can see the experimental patch at http://issues.apache.org/jira/browse/HARMONY-857):
- I have added JNI_CreateJavaVM declaration to jni.h (guess it will be the most appropriate place for it); - Added a simple implementations for JNI_CreateJavaVM and DestroyJavaVM based on the existing create_vm and detroy_vm functions in the vmcore/init submodule. - To make vmcore/init functions visible for vmcore/jni code, I have moved vmcore/init/init.h to vmcore/include; - In parse_arguments.cpp, I had to silently ignore the option "_org.apache.harmony.vmi.portlib" which is passed by the launcher to VM for some reason, causing the DRLVM to complain about "unknown option". What is the purpose of that option, should I process it differently? After all, I was able to run the DRLVM under classlib's launcher on Windows with a command like: Java.exe -vm:vmcore -vmdir:. Hello and even was able to run Eclipse IDE with it. VM seems to exit cleanly and didn't report any error messages. Some of the remaining issues / observations are: (1) DRLVM startup is organized a bit differently compared to the classlib launcher startup, namely – the DRLVM after creating VM runs a special class called VMStart which is, in it's turn, asynchronously calling the main() method of the user application in a separate thread. When we go with the classlib's launcher, the main() method is executed in the same thread where the JavaVM is created. What are the caveats with that? (2) If I pass a wrong app class name to the classlib launcher, drlvm reports class not found exception and then is crashed. This happens because the classlib launcher, once it fails to run the app class, reports an exception (with ExceptionDescribe) but doesn't clear it (doesn't call ExceptionClear). Then it immediately goes with DestroyJavaVM those current implementation in drlvm doesn't expect that there is some pending exception object in the TLS. Eventually, destroy_vm fails with assert in the class loading code while resolving VMStart class (VMStart holds the Java part of the shutdown method), because it mistakenly picks up the ClassNotFound exception object. It is remaining from unsuccessful attempt of classlib launcher to run the app's class main method. The question is, who's responsibility should be to clear the exception object in that case? I tend to think that classlib launcher should be doing this once it takes the responsibility to process the possible exceptions while running the app main class. (3) CreateJavaVM can only be called once for now – many internal data structures in DRLVM are kept as global variables (jni_env, java_vm, Global_Env e.t.c.). Therefore, it will be hard to organize the multiple instances of JavaVM unless all these things are encapsulated somewhere (into JNIEnv?). (4) Launcher wants the vm dll in the "default" directory unless the option is specified. Should we realign the drlvm build output and move all dll's into the "default" subdir? (5) What to do with the "_org.apache.harmony.vmi.portlib" option that launcher is offering to VM? Most likely there are more issues that I'm overlooking at the moment. Please consider the suggested patch is a workaround to make the things working, I'm wondering if there is a more graceful way to do this. Thanks, Andrey. On 7/11/06, Andrey Chernyshev <[EMAIL PROTECTED]> wrote:
OK, so I'm going to add CreateJavaVM into vm\vmcore\src\jni\jni.cpp and also add implementation into DestroyVM (stub is already seem to be present there) based on destroy_vm(). Then we'll see how it works with the launcher. Thanks, Andrey. On 7/11/06, Geir Magnusson Jr <[EMAIL PROTECTED]> wrote: > This has been my thinking - even if not perfect, lets get it working > using the launcher and then fix as required. It's arguable if that > "brokenness" matters at this point, and I think that there's plenty to > be gained from having it work via the launcher. > > geir > > Rana Dasgupta wrote: > > create_vm() looks quite close/complete to being a complete prototype for > > CreateJavaVM, > > but I think more work is needed in DestroyVM which prototypes DestroyJavaVM > > for functional completeness. It is non waiting on user threads, it does not > > send the corresponding JVMTI shutdown events, I also don't know if it > > handles shutdown hooks cleanly ( but these "may" not be critical right now > > for hooking up to the launcher ). What do you think? > > > > When I ran a non trivial test.. upto 32 threads instantiating a very large > > number of objects with -XcleanupOnExit which uses DestroyVM, it > > exited cleanly. Maybe OK to hookup and fix bugs as we go. > > > > Thanks, > > Rana > > > > > > On 7/10/06, Andrey Chernyshev <[EMAIL PROTECTED]> wrote: > > > >> >Yes, it seems like the launcher will need at least JNI_CreateJavaVM > >> >and DestroyJavaVM functions. > >> > >> >I couldn't find implementation for CreateJavaVM in drlvm codebase. > >> >Perhaps create_vm() function in vm\vmcore\src\init\vm_main.cpp can be > >> >adopted for that purpose? > >> >Is there are any tricks and caveats one should be aware of before > >> >trying to produce CreateJavaVM from it? > >> > >> >I've also seen a prototype for DestroyJavaVM in > >> >vm\vmcore\src\init\vm.cpp - comment says it needs to be improved to > >> >wait till all Java threads are completed. > >> > >> >Any more ideas what needs to be done to implement those? > >> > >> >Thanks, > >> >Andrey. > >> > >> > >> --------------------------------------------------------------------- > >> Terms of use : http://incubator.apache.org/harmony/mailing.html > >> To unsubscribe, e-mail: [EMAIL PROTECTED] > >> For additional commands, e-mail: [EMAIL PROTECTED] > >> > >> > > > > --------------------------------------------------------------------- > Terms of use : http://incubator.apache.org/harmony/mailing.html > To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, e-mail: [EMAIL PROTECTED] > > -- Andrey Chernyshev Intel Middleware Products Division
-- Andrey Chernyshev Intel Middleware Products Division --------------------------------------------------------------------- Terms of use : http://incubator.apache.org/harmony/mailing.html To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
